Apparatus for treating ion beam

Abstract

An ion beam scanning assembly includes a set of scanning electrodes defining a gap to accept an ion beam and scan the ion beam in a first plane, and a multipole electrostatic lens system comprising a plurality of electrodes arranged along a portion of a path of travel of the ion beam bounded by the pair of scanning electrodes, the multipole electrostatic lens system configured to shape the ion beam in a direction perpendicular to the first plane.

What is claimed is: 
     
       1. An ion beam scanning assembly comprising:
 a set of scanning electrodes defining a region therebetween to transmit an ion beam and scan the ion beam in a first plane, the set of scanning electrodes oriented perpendicularly to the first plane; and 
 a multipole electrostatic lens system comprising a plurality of electrodes oriented parallel to the first plane, wherein the multipole electrostatic lens system is superimposed on the set of scanning electrodes, wherein the multipole electrostatic lens system and the set of scanning electrodes bound the ion beam along a same portion of a beam path traversed by the ion beam, the multipole electrostatic lens system configured to shape the ion beam in a direction perpendicular to the first plane within the region. 
 
     
     
       2. The apparatus of  claim 1 , wherein the multipole electrostatic lens system is a quadrupole electrostatic lens system configured to shape alter the size and the density of the ion beam, the quadrupole electrostatic lens system comprising:
 a first lens comprising a first pair of opposed electrodes and a second pair of opposed electrodes configured to bound opposite sides of the ion beam path over a first segment of the portion of the ion beam path; 
 a second lens downstream of the first lens along the ion beam path, the second lens comprising a third pair of opposed electrodes and a fourth pair of opposed electrodes configured to bound opposite sides of the ion beam path; and 
 a set of voltage generators configured to apply a plurality of respective voltages to the first through fourth pair of opposed electrodes, wherein the plurality of voltages generate a set of electric fields perpendicular to the ion beam path. 
 
     
     
       3. The apparatus of  claim 2 , wherein the plurality of voltages comprises DC positive voltages within a range of 0 to 50 kV. 
     
     
       4. The apparatus of  claim 3 , wherein the plurality of voltages comprises DC positive voltages within a range of positive voltage greater than 0 volts up to 50 kV. 
     
     
       5. The apparatus of  claim 2 , wherein the plurality of voltages comprises DC negative voltages within a range of 0 to −50 kV. 
     
     
       6. The apparatus of  claim 5 , wherein the plurality of voltages comprises DC negative voltages within a range of negative voltage less than 0 volts up to −50 kV. 
     
     
       7. The apparatus of  claim 2 , wherein the plurality of voltages comprises oscillating voltages having amplitudes within a range of −25 kV to +25 kV and frequencies within a range of 100 to 2000 Hz. 
     
     
       8. The apparatus of  claim 2 , wherein the plurality of voltages are configured to expand the ion beam in the direction perpendicular to the first plane. 
     
     
       9. The apparatus of  claim 2 , wherein the plurality of voltages are configured to compress the ion beam in a direction of the first plane, and stretch the ion beam in a direction perpendicular to the first plane. 
     
     
       10. The apparatus of  claim 1 , wherein one or more pairs of electrodes of the set of scanning electrodes are operative to generate a respective one or more voltage waveforms that each comprises an oscillating voltage superimposed on a DC offset voltage, wherein an amplitude of the oscillating voltage with respect to the DC offset voltage is within a range of −25 kV to +25 kV, wherein the frequency of the oscillating voltage is within a range of 100 to 2000 Hz, and wherein the DC offset voltage is within a range of −25 kV to +25 kV. 
     
     
       11. The apparatus of  claim 1 , wherein one or more pairs of electrodes of the set of scanning electrodes are configured to apply respective one or more oscillating electric fields to scan the ion beam. 
     
     
       12. The apparatus of  claim 1 , wherein one or more pair of electrodes of the set of scanning electrodes are configured to generate respective one or more voltage waveforms that each comprises an oscillating voltage that is superimposed on a DC offset voltage, the oscillating voltage being configured to produce the oscillating field and the DC offset voltage being configured to alter the shape, size and the density of the ion beam. 
     
     
       13. The apparatus of  claim 1 , wherein one or more pair of electrodes of the set of scanning electrodes comprises a length along the beam path of about 50 to 300 mm. 
     
     
       14. The apparatus of  claim 1 , wherein one or more pair of electrodes of the set of scanning electrodes have a height in a direction perpendicular to the ion beam path of about 50 mm to 150 mm. 
     
     
       15. A method of treating an ion beam, comprising:
 using a set of scanning electrodes defining a region therebetween to transmit an ion beam and scan the ion beam in a first plane, wherein the set of scanning electrodes are oriented perpendicularly to the first plane; 
 generating one or more oscillating electric fields along the first plane perpendicular to the ion beam within the region; 
 applying a first set of non-zero voltages to a first lens of a multipole electrostatic lens system, the first lens comprising a first pair of opposed electrodes and a second pair of opposed electrodes configured to bound opposite sides of the beam over the region; and 
 applying a second set of voltages to a second lens of the multipole electrostatic lens system, the second lens comprising a third pair of opposed electrodes and a fourth pair of opposed electrodes configured to bound opposite sides of the beam path over a second segment of the portion of the beam path further from an ion source to generate the ion beam, wherein the first lens and second lens of the multipole electrostatic lens system comprise a plurality of electrodes oriented parallel to the first plane and configured to shape the ion beam within the region, wherein the multipole electrostatic lens system is superimposed on the set of scanning electrodes, wherein the multipole electrostatic lens system and the set of scanning electrodes bound the ion beam along a same portion of a beam path traversed by the ion beam. 
 
     
     
       16. The method of  claim 15 , further comprising providing the first and second voltages as DC positive voltages within a range of voltages greater than zero volts up to 50 kV. 
     
     
       17. The method of  claim 15 , further comprising providing the first and second voltages as DC negative voltages within a range of voltages less than zero volts to −150 kV. 
     
     
       18. The method of  claim 15 , further comprising providing a respective oscillating voltage to the one or more pair of electrodes of the electrostatic scanner component having an amplitude within a range of −25 kV to +25 kV and frequency within a range of 100 to 2000 Hz. 
     
     
       19. The method of  claim 15 , the generating the one or more oscillating electric fields further comprising providing respective one or more oscillating voltages as an oscillating voltage waveform comprising an oscillating voltage component that is superimposed on a DC offset voltage, wherein an amplitude of the oscillating voltage component with respect to the DC offset voltage is within a range of −25 kV to +25 kV, wherein a frequency of the oscillating voltage component is within a range of 100 to 2000 Hz, and wherein the DC offset voltage is within a range of −25 kV to +25 kV.